Math 150 Midterm 2- Page 8 of 8 November 201 (d) (4 points) Use the range rule o
ID: 3360243 • Letter: M
Question
Math 150 Midterm 2- Page 8 of 8 November 201 (d) (4 points) Use the range rule of thumb to find the minimun usual value and the maxigum usual value. (e) (4 points) According to part (d), is x = 100 an unusual value? Why? If yes, it is an unusually low value or an unusually high value? 7, (12 points) Based on a Harris Interactive poll, 80% of students believe that one can perform well in college math classes through hard work. Assume that .six students are randomly selected. Let random variable a be the number of students who believe in hard work. Find the indicated probability (keep four decimal places). (a) (3 points) What is the probability that exactly five of the sclected students believe in hardExplanation / Answer
7.
BIONOMIAL DISTRIBUTION
pmf of B.D is = f ( k ) = ( n k ) p^k * ( 1- p) ^ n-k
where
k = number of successes in trials
n = is the number of independent trials
p = probability of success on each trial
I.
mean = np
where
n = total number of repetitions experiment is excueted
p = success probability
mean = 6 * 0.8
= 4.8
II.
variance = npq
where
n = total number of repetitions experiment is excueted
p = success probability
q = failure probability
variance = 6 * 0.8 * 0.2
= 0.96
III.
standard deviation = sqrt( variance ) = sqrt(0.96)
=0.9798
a.
probability that exactly 5 of selected students believe in hard work
P( X = 5 ) = ( 6 5 ) * ( 0.8^5) * ( 1 - 0.8 )^1
= 0.3932